Method and system of lithography using masks having gray-tone features
US6884551B2 · kind B2 · utility
16Cited by
13References
108Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 4, 2002 |
| Grant date | Apr 26, 2005 |
| Priority date | — |
| Expiry date | Dec 19, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70283
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method forms patterns on a substrate by exposing the substrate a first time and exposing the substrate a second time using a mask containing gray-tone features. The gray-tone features locally adjust an exposure dose in regions corresponding to features defined in the primary exposure. Moreover, the gray-tone features enable the forming of features having different critical dimensions on a substrate. The gray-tone features may be sub-resolution features and formed by pixellation. The trim mask containing gray-tone features may have regions with different transmissivities.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.